Shearing apparatus with workpiece-viewing means

ABSTRACT

A shearing apparatus wherein a portion of a workpiece which projects over a table edge is sheared off by a generally vertically reciprocable blade while the workpiece is held firmly against the table by a clamping element. A viewer affords the operator an enlarged view of the workpiece in the gap between the clamping element and the blade. The viewer has a high-intensity light source which directs a beam of light at the workpiece in the gap and a reflector and lens arranged to direct to the operator the light reflected by the workpiece. A translucent screen can be provided to afford the operator a picture-like view regardless of his position.

US] 3,656,391 1 Apr. 18,1972

United States Patent Von Arx X 0 2 s N m 5 MN Mm T. WA mm ML a M 0 6 m mN E T m wN 6 MB R O 4:: 8 2

[54] SHEARING APPARATUS WITH WORKPIECE-VIEWIN G MEANS [72] Inventor:Paul Von Arx, Gelterkinderstrasse 31, ch

4450, Sissach, Switzerland Feb. 20, 1970 576,659 5/1933Germany................................

548552 4/1932 Germany.......

[22] Filed:

Primary Examiner-James M. Meister Attorney-Kari F. Ross [21] Appl. No.:

ABSTRACT [30] Foreign Application Priority Data 3,034,388 5/1962Stoothhoffeta]...... 3,304,834 2/1967Olifischeta].......................

.83/521 X 9 Claims, 5 Drawing Figures sum 10F 3 PHENTEUAPRIe m2 Paul VanArx INVENTOR.

' Attorney k H H 8 k l Q & m u x Qu v N x v m. P... v v H Q a 7 .3

PATENTEDAPR 18 m2 SHEET 2 BF 3 Paul Von Arx IN VENTO R.

R1 Attorney FIG. 3

PATENTEDAPR 18 I972 SHEET 3 BF 3 Paul Von Am INVENTOR 55 4w R9 AttorneySHEARING APPARATUS WITH WORKPIECE-VIEWING The present invention relatesto a shearing apparatus. More particularly, this invention relates tosuch an apparatus as is used in manufacturing shops to cut metal platesor other similar heavy sheet-like material.

Such devices have a table on which the workpiece to be cut is positionedwith the portion to be cut ofi projecting beyond the table edge awayfrom the operator. A clamping element or shoe is pressed against theworkpiece when it has been properly positioned, and a heavy blade dropsto shear the projecting portion substantially flush with the table edge.

For normal rough work an'apparatus of this type is quite adequate and,when a great many similar cutsmust be made, a stop is often provided sothat the workpiece need merely be pushed against this stop to make thesame cut every time.

As a matter of fact, it is practically impossible to cut accurately withsuch an apparatus when the cut must be made at a mark on the workpiecebecause the operator finds it extremely difficult to see just how the.workpiece is positioned under the blade. The clamping element, even inthe up position, partially obstructs the workpiece, and in the downposition thoroughly blocksthe view. The apparatus is usually provided ina closed housing so that any flying chips or splinters produced by theshearing operation cannot injure the operator. Even when the housing isnot fully closed and some light is directed on the workpiece adjacentthe blade, this area must be viewed from above and from a distancecausing inconvenience and loss of accuracy.

In another improved method of the prior art, a light beam is directeddirectly in line with the blade so that a shadow is cast which coincidesperfectly with the place where the blade will strike and cut theworkpiece. This is useful with printed circuits and name plates.Nonetheless, it is still necessary that the operator somehow, by peeringin the feed slot or down into the machine, get a look at just where theblade shadow falls. This is very difficult and none too accurate.

It is, therefore, an object of the present invention to provide animproved shearing apparatus which overcomes the abovementioneddrawbacks. Y e

Another object of this invention is to provide a shear capable ofconvenient operation at high accuracy.

Yet another object of the present invention is to provide a shearingapparatus that permits simple, strainless and accurate viewing of thecutting area by the operator prior to and during each cut.

These objects are attained, in accordance with the inven- 7 tion, with ashearing apparatus having viewing means including a light sourcedirecting a light beam upon the marked surface of a workpiece in the gapbetween the blade and the clamping element. A reflector above the tablecollects light reflected by the workpiece from the beam to provide theoperator with a view of the workpiece in the gap. Both the light sourceand the reflector are arranged between the planes of the clampingelement and the blade so that the workpiece can be observed easily whenthe light is reflected out horizontally to eliminate any necessity ofmovement by the operator from his position in front of the loading slotof the apparatus.

According to another feature of this invention, the viewing means oroptical path includes lenses which enlarge the image so that theoperator can very accurately see and position the workpiece. Furtherguide means, such as a horizontal thread coplanar with the blade or apair ofvertically spaced horizontal threads lying in a vertical plane inline with the blade serve to judge very exactly where the cut willbe'made, even when the clamping element is down. With a single threadthe position of the eye of the viewer may cause inaccuracies, the use oftwo threads permits alignment with greater precision.

In accordance with a further feature of the present invention, theenlarged image of the cut region is projected on a screen so that theoperator will not have to move his head around to see just how the bladeand the workpiece are lined up. This screen is advantageously tinted toeliminate any harsh retlectionsfrom the usually metallic workpiece.

The above and other objects, features and advantages will becomeapparent from the following description, reference being made-to theaccompanying drawing, in which:

FIG. 1 isa vertical sectional view of a first embodiment of theapparatus according to the present invention;

FIG. 2 is a similar view of a second embodiment of the ap paratusaccording to the present invention;

FIG. 3 is a side sectional view of a third embodiment of the apparatusof this invention;

FIG. 4 is a detail view of an alternative form of FIG. 3, and

FIG. 5 is a section taken along line V-V of FIG. 2.

As seen in FIG. I, the apparatus has a housing 1 provided with a table 2having a reinforcing edge member 3. A workpiece M can be clamped to thetable 2 by a clamping element 4 to have the portion of it which projectsover the edge 3 cut off by a blade 5" carried on a verticallyreciprocable beam 6 The clamping element 4 is elongated and flat andextends at an angle a of l5-20, preferably about 17, tothe vertical. Ahydraulic actuating arrangement shown schematically at 24 is operable tomove the element 4 downwardly, it being springbiased into theillustrated up position. The beam 6 and blade 5 are similarly elongatedand flat and extend vertically, as does the edge 3 of the table 2. Asshown in FIG. 5, the cutting edge 5a of the blade 5 is inclined to thecutting edge 3a of the edge member 3 to facilitate shearing. A hydraulicactuating device 25 displaces the beam 6 downwardly as does the device24.

The housing has side plates 7' and 7", a top cover plate 7, and a frontplate 8 which serve to protect the operator from chips and keep straylight from falling on the workpiece in the gap G between the elements 4and 5. Mounted via a bracket to this plate 8 are a pair of elongatedhigh-intensity lamps 9 which directa strong light beam on the workpiecein the gap G. The reflected light from the workpiece is picked up andreflected by a rotatably adjustable mirror 10 through a magnifying lens12 held in a tube 11. This piano-convex lens 12 is a bar lens whichfocuses on a point A. Lining the blade surface 5 up with the line on theworkpiece which is to be cut is aided by a horizontal thread 13 coplanarwith the blades. Instead of this single thread, a pair of horizontalthreads shown at the dots 13 can be used. In this latter case the twothreads or filaments are lined up one over the other by shifting theoperators head, by positioning the operator with respect to the viewerby raising or lowering the seat 2, or by vertically shifting the viewerassembly 10, 11, 12 in a guide 10', and the line on the workpiece M tobe cut is moved under the single line formed thereby. With a singlethread 13 the operator positions his eye so that the thread appears inline with the. blade and lines up the mark on the workpiece therewith.Vertical threads may be used, in which case, when the viewer is properlypositioned, they appear as dots and permit lining the marking on theworkpiece up thereunder. Then the operator need only actuate the devices24 and 25 to cut off accurately the projecting workpiece end. In thisembodiment the image is a magnified virtual image lying in an imageplane beyond the mirror. t

The reference numerals of FIG. lappearing in FIGS. 2 and 5 apply tofunctionally identical structure wherever they appear. In the secondembodiment of FIG. 2 there is provided a light source 15 consisting ofan elongated housing 26 in which is mounted a lamp 16 whose ends arereceived in sockets 32 with a reflector l7. The housing 26 is mounted onpins 30 passing through side walls 7' and 7" of the housing and carryingnuts 29 which can be tightened to hold the housing 26 in any angularposition. A narrow portion 31 of the housing 26 holds plano-convex barlens 18 which serves to focus the light of lamp 16 on the gap G. Thereflected light passes through a biconvex beam lens 19 whence it isreflected by a mirror 20 mounted on pins 28 carrying tightening nuts 27onto a translucent screen 21' mounted in a viewing tube 22 which keepsstray light off this screen 21.

FIG. 5 also shows a double-headed arrow indicating a 7 distance dwhichis equal to thewidth of the feed slot 8' (see FIGJl). Also, thelens 19 is shown with an upper surface 19' curved in two dimensions sothat it will enlarge the workpiece image in two dimensions to give theprojection seen by the operator on the screen 21 a width D which isgreater than the maximum workpiece width d. The workpiece is seenenlarged in two dimensions so that delicate positioning of, for example,printed circuit boards is easily carried out. As in the embodiment ofFIG. 1, the picture seen by the operator is an upright virtual image.

This embodiment is used the same as that of FIG. 1, except that with itthere is no problem with the position of the operators head since thenuts 27 and 29 are adjustable to line the image up correctly on thescreen 21. As in the previous embodiment, the image seen by the operatoris enlarged.

FIG. 3 shows a third embodiment which is identical with that of FIGS. 2and except that the table 2 is inclined relative to the horizontal,thereby making it easier for the operator, and there is provided achannel carrying a pair of mirrors 20' and 20" instead of the singlemirror 20 to reflect the light on a screen 21'. The screen 21' is tintedso that any harsh or harmful reflections are muted and do not irritatethe operator. Furthermore, the clamping beam 4 is here provided with arubber foot 4' to prevent marring of the workpiece M In FIGS. 1 and 2the light reflected from the workpiece is further reflected through 90,FIG. 3 shows how a greater angle B is possible between the reflectedbeam and viewing axis.

FIG. 4 shows a pentaprism 23 which has a pair of polished faces 20a and2011 which can be used in the place of the channel 23 and mirrors 20'and 20".

The apparatus shown in FIG. 3 is extremely easy to operate. The operatorneed merely feed the workpieces M in the slot 8' and observe in thescreen 21 when the desired marking appears in line under the blade 5.Then the clamp actuator 24 is operated, usually by a pedal, and, if thishas not moved the workpiece out of line, the actuator 25 is actuated,usually by another pedal, to cut off the workpiece end. The slot 8 is sonarrow that fingers cannot be placed in danger under either of theelements 4 or 5, another feature rarely provided in priorart devicessince the workpiece must be viewed through the feed slot 8.

It is worth noting that the light from the source 9 or never fallsdirectly on the reflector 10, 20, and 20", or 23, shielding in the formof the housing 26 or bracket 9' being provided in all cases. In generalthe reflected beam from the workpiece parallel to the movable blade iscollected by the reflecting means and further reflected at least oncealong an optical axis transverse to this plane.

Iclaim:

1. A shear comprising:

a table having a table edge and adapted to receive a workpiece restingon said table with a portion projecting beyond said edge;

blade means rectilinearly reciprocal above said table and having acutting edge cooperating with said edge for movement in a blade planefor shearing said portion off said workpiece; and

viewing means including a light source directing a light beam againstsaid workpiece at said table edge and a reflector above said table insaid blade plane for directing light reflected along said plane by saidworkpiece from said beam to an operator for affording a view of theprecise location on said workpiece to be engaged by said cutting edge onshearing off of said portion.

2. The shear defined in claim 1, further comprising clamping meansincluding a clamping element adjacent said blade defining a gaptherewith and engageable with said workpiece for holding same againstsaid table during shearing, said beam being directed against workpiecein said gap.

3. The apparatus defined in claim 2 wherein said viewing means includesat least one lens in the path of the reflected light for affording saidoperator with an enlarged view of said workpiece in said gap.

4. The apparatus defined in claim 3 wherein said viewing means includesat least one filament in said plan. I

5. The apparatus defined in claim 3 wherein said viewing means includesa screen, said reflector reflecting light onto said screen to affordsaid view.

6. The apparatus defined in claim 3 wherein said reflector has at leasttwo flat reflecting surfaces.

7. The apparatus defined in claim 6 wherein said reflector is a prism.

8. The apparatus defined in claim 2 wherein said clamping element isdisplaceable in a plane inclined to said blade means.

9. The apparatus defined in claim 2 wherein said blade means includes avertically displaceable elongated blade, said clamping element beingelongated and displaceable toward and away from said table in a planeinclined to said blade plane and to said table, said viewing meansincluding lens means including at least one bar lens for affording saidoperator with an enlarged view of said workpiece in said gap and anelongated lamp, said reflector being arranged and constructed to reflectthe light reflected by said workpiece substantially horizontally towardsaid operator.

1. A shear comprising: a table having a table edge and adapted toreceive a workpiece resting on said table with a portion projectingbeyond said edge; blade means rectilinearly reciprocal above said tableand having a cutting edge cooperating with said edge for movement in ablade plane for shearing said portion off said workpiece; and viewingmeans including a light source directing a light beam against saidworkpiece at said table edge and a reflector above said table in saidblade plane for directing light reflected along said plane by saidworkpiece from said beam to an operator for affording a view of theprecise location on said workpiece to be engaged by said cutting edge onshearing off of said portion.
 2. The shear defined in claim 1, furthercomprising clamping means including a clamping element adjacent saidblade defining a gap therewith and engageable with said workpiece forholding same against said table during shearing, said beam beingdirected against workpiece in said gap.
 3. The apparatus defined inclaim 2 wherein said viewing means includes at least one lens in thepath of the reflected light for affording said operator with an enlargedview of said workpiece in said gap.
 4. The apparatus defined in claim 3wherein said viewing means includes at least one filament in said plan.5. The apparatus defined in claim 3 wherein said viewing means includesa screen, said reflector reflecting light onto said screen to affordsaid view.
 6. The apparatus defined in claim 3 wherein said reflectorhas at least two flat reflecting surfaces.
 7. The apparatus defined inclaim 6 wherein said reflector is a prism.
 8. The apparatus defined inclaim 2 wherein said clamping element is displaceable in a planeinclined to said blade means.
 9. The apparatus defined in claim 2wherein said blade means includes a vertically displaceable elongatedblade, said clamping element being elongated and displaceable toward andaway from said table in a plane inclined to said blade plane and to saidtable, said viewing means including lens means including at least onebar lens for affording said operator with an enlarged view of saidworkpiece in said gap and an elongated lamp, said reflector beingarranged and constructed to reflect the light reflected by saidworkpiece substantially horizontally toward said operator.